This invention is generally directed to ladder polymers and to imaging members thereof. More specifically, the present invention is directed to ladder polymer infrared photogenerating pigments, and imaging members thereof. In one embodiment of the present invention, there are provided layered photoconductive imaging members with improved xerographic properties, inclusive of high charge acceptance, low dark decay, high photosensitivity in the wavelength regions of from about 700 to about 820 nanometers, and maximum or peak photosensitivity in the wavelength regions of from about 750 to about 760 nanometers, enabling their selection for electrophotographic, especially xerographic, imaging systems and printers sensitive to near infrared wavelengths. In one embodiment imaging members with photoconductive layers comprised of the ladder polymers illustrated herein, and charge or hole transport layers, especially those comprised of aryl amines, which members are sensitive to light in the wavelength region of from about 700 to about 820 nanometers. The resulting members are responsive to red illumination originating from light emitting diode (LED) printing apparatuses. The photoresponsive imaging members of the present invention can, for example, contain situated between a photogenerating layer and a charge transporting layer, or situated between a photogenerating layer and a supporting substrate with a charge transport layer in contact with the photogenerating layer, a photoconductive composition comprised of the ladder polymer photogenerating pigments illustrated herein.
In another embodiment of the present invention, there are provided imaging members with a photoconductive layer comprised solely of the ladder polymers illustrated herein, that is an imaging member with a layer that functions simultaneously both as charge generating layer and transport layer.
Certain layered imaging members are known, including those comprised of separate generating layers, and transport layers as described in U.S. Pat. No. 4,265,990, the disclosure of which is totally incorporated herein by reference; and overcoated photoresponsive materials containing a hole injecting layer overcoated with a hole transport layer, followed by an overcoating of a photogenerating layer; and a top coating of an insulating organic resin, reference U.S. Pat. No. 4,251,612. Examples of photogenerating layers disclosed in these patents include trigonal selenium and phthalocyanines, while examples of transport layers include certain diamines as mentioned therein.
The following United States patents are mentioned: U.S. Pat. No. 4,299,896 which discloses imaging members with a photosensitive layer selected from the disazo pigments of the formulas illustrated, for example, in the Abstract, and in column 2; U.S. Pat. No. 4,314,015 wherein the disazo pigments for the imaging member are of the formula as illustrated in the Abstract, for example, and column 2; U.S. Pat. No. 4,666,810 wherein the azo pigments are illustrated in column 2 for example; and U.S. Pat. No. 4,797,337 wherein the disazo photogenerating pigment is of the formula as illustrated in the Abstract, for example, which disazos may contain a SO.sub.2 group.
U.S. Pat. No. 4,713,307, the disclosure of which is totally incorporated herein by reference, discloses photoconductive imaging members containing a supporting substrate, certain azo pigments as photogenerating materials, and a hole transport layer that preferably contains an aryl diamine compound dispersed in an inactive resinous binder.
U.S. Pat. No. 4,797,337, the disclosure of which is totally incorporated herein by reference, discloses a photoconductive imaging member comprising a supporting substrate, a hole transport layer, and a photogenerating layer comprising specific disazo compounds.
Additional references illustrating layered organic electrophotographic photoconductor elements with azo, bisazo, and related compounds include U.S. Pat. Nos. 4,390,611, 4,551,404, and 4,596,754, Japanese Patent 60-64354, U.S. Pat. Nos. 4,400,455, 4,390,608, 4,327,168, 4,299,896, 4,314,015, 4,486,522, 4,486,519, 4,555,667, 4,440,845, 4,486,800, 4,309,611, 4,418,133, 4,293,628, 4,427,753, 4,495,264, 4,359,513, 3,898,084, 4,830,944, and 4,820,602, and Japanese Patent Publication 60-111247.
U.S. Pat. No. 4,755,443 discloses a photoreceptor for electrophotography which comprises a charge carrier generating material and charge transport material wherein one charge generating material is a metal phthalocyanine or a metal-free phthalocyanine. The layer containing the generator material also contains an organic amine. Other carrier generating substances can be used in combination with the phthalocyanine generator material, including azo pigments, anthraquinone dyes, perylene dyes, polycyclic quinone dyes, and methine stearate pigments.
U.S. Pat. No. 4,424,266 discloses an electrophotographic photosensitive element having a conductive support and a photosensitive layer comprising a carrier generating phase layer containing a carrier generating material selected from the group consisting of perylene dyes, polycyclic quinones, and azo dyes, and a carrier transporting phase layer containing a hydrazone carrier transporting material. The carrier generator materials can be used either singly or in combination.
U.S. Pat. No. 4,882,254, the disclosure of which is totally incorporated herein by reference, discloses a layered photoresponsive imaging member which comprises a supporting substrate, a photogenerator layer comprising a mixture of first and second pigments, and an aryl amine hole transport layer. The mixture of pigments is selected from perylenes and phthalocyanines, polycyclic quinones and phthalocyanines, or perinones and phthalocyanines.
Photoresponsive imaging members containing perinone and perylene compounds are also known. For example, European Patent Publication 0040402, DE3019326, filed May 21, 1980, discloses the use of N,N'-disubstituted perylene-3,4,9,10-tetracarboxyldiimide pigments as photoconductive substances.
Imaging members with phthalocyanine materials are also known as disclosed in, for example, U.S. Pat. Nos. 3,594,163, 3,657,272, 3,816,118, 3,862,127, 3,903,107, 3,927,026, 3,932,180, 3,932,454, 4,031,109, 4,098,795, and Re. 27,117, the disclosures of each of which are totally incorporated herein by reference.
The disclosures of each of these patents and publications are totally incorporated herein by reference.